Valve mechanism for air-compressors.



, .S. PAIRI-IURST,

VALVE MECHANISM FOR AIR OOMPRESSORS.

, APPLICATION FILED NOV. 16, 1911.; 1,073,337. Patented Sept. 16, 1913.

2 SHEETSSHEBT 1,

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-VMVE MEEHANISM FOR AlIR-GOMPRZESSUML spe im n: or Eettcrs- Patent.

Patented 16, 1913'.

Applicatiomfiled November 16 I911. Serial No, 666,690.

To all whom 'z't'ma'y concern:

Be it known that I, WILLIAM S. FAIR nuas'r, a citizen of the UnitedStates, andresidentof the borough of Brooklyn, inthe city and State 01?New York, have invented a new i and useful; Improvement inValveMechanism for Air-Compressors, of which the following is aspecification.

My inventionrelates to valve mechanism for air'ccmpressors,-the objfectbeing v to prevent noise and hammering axt'whatever speed the compressoris operated.

A practical embodiment of my invention is represented in theaccompanyingdrawv; ings, in which,

Figure 1 is a top planview of a compressor and its valves, Fig.2 is aview'in' side elevation,- and! Fig, 3 is a horizontal section on alarger scale: a

The low pressure or main compressor cyl inder is denoted by 1', itspiston by-2 and the piston rod by 3. The rod- 3 and; hence thepiston, isdrivenffrom adriveshaft 4.

At the opposite ends of the cylinder 1, ports 5 and 6 lead to.pistoncylinders 7 and 8, in which pistons 9' and 19* work, fixed on apiston-rod 11 common to the twopistons and driven by the drive shaft 4.

The cylinders 7 and 8 are conveniently located in juxtaposition to themain cylinder 1, and the cylinder 1 is fed from an air inlet chamber 12intermediate of the cylinders 7 and 8 and provided with an air inletport 13.

At the outer end of the cylinder "7, there is located'a valve box 14around the wall of which is located an outlet chamber 15 into Whichthecompressed air is forced from the cylinder 7, through a port or ports16, opened and closed by the ,valve 17. The valve 17 is mounted to slideon a spindle,

preferably a hollow spindle, 18, tapped into the hub 19 of a skeletonplate 20 forming the inner end of the valve b02114. The valve 17 seatsagainst the inwardly projecting margin of the end 20 and against theinner end of the hub 19 around the spindle 18, when in position to closethe port or ports 16, as shown in Fig. 3. The outer face of the valve 17is dished cone-shape and is held normally away from the projectingconeshape end of a nut 21 screwed on the thread ed outer portion of thespindle 18, by an interposed spring 22. A look nut 23 holds the stop nut21 in its adjusted position to limit the throw of the valve 17 and applythe desired tension to the spring 22, and an annular nut 24; on the endof the spindle 18 fits 1n a socket 2:; in the end cap 26 of the valvebox to holdthe spindle 18 against vibration.-

To further deadensoundand prevent leakage, an elastic washer 27 may bein sorted between the bottom of the socket 25 and the end of the spindle18. In like manner the cylinder 8 communicates with a valve bo s-28surrounded by an outlet chamber 29 which communicates with the interiorof the cylinder 8, through a port or ports 30,

opened? and closed by a sliding valve* 31 mounted on a spindle 32 andhaving its throw limited by a nut 33, between which and the valve aspring .34 is located, the

structureand operation of the several parts municationwith the spaceback of the cutoff valve, the former through a small port 35 and thelatter through a sinall port 36 in the Wall of the valve box'. Thevalves 17 and 31 are thus balanced and close promptly under theinfluence of their actuating springs the moment the piston 9 or 10completes its compression stroke.

The ports 16 and 30 are made winding or spiral to assist in causing thevalves 17 and 31' to slide smoothly. The outlet chambers 15 and 29communicate with an intercooler or storage receptacle of any well knownor approved form, not shown, through the out- ;let openings 37, 38, seeFig. 1.

In operation, as the piston 2 begins its stroke to the right, the piston9 moves to the left, opening the port 5 and admitting a charge of airinto the cylinder 1 through the inlet 13; At the same time, the piston10 opens the port 6 and the air is compressed in the space between thepiston 10 and valve 31 until it overcomes the pressure in 29 and opensthe valve 31. The pistons 9 and 10 then move to the right, the piston 10closing the port 6 just before the piston 2 begins to move to the leftand the compressed air between the piston 10 and valve 31 is forcedthrough valve 31 and delivered into the chamber 29, the valve 31promptly closing under the influence of its spring 351, the moment thepiston 10 stops its advance movement. The same cycle of steps takesplace at the opposite end of the compressor A stroke to the left.

The valves are noiseless, they close with out shock or hammering becausethey are cushioned on both sides and balanced by compressed air andspring, the tension of the latter and the throw of the valve beingadjusted by the stop nut. These advantages of structure admit of highspeed and great efiiciency.

What I claim is:

1. In an air compressor, a main compressor cylinder, a piston cylinderin cooperative relation thereto, a valve box at the end of the pistoncylinder, an outlet chamber in communication with the valve box, the endof the valve box adjacent to the piston cylinder being of skeletonstructure and provided with annular valve seats on its inner face, avalve guiding spindle fixed in the central portion of said skeleton end,a valve mounted to slide on said spindle to open and close communicationbetween .the valve box and outlet chamber, a valve stop having ascrew-threaded engagement with said spindle, a spring interposed betweenthe valve and stop and a lock nut to hold the stop in the desiredadjustment to regulate the tension of the spring.

2. In an air compressor, a main compressor cylinder, a piston cylinderin co operative relation thereto, a valvebox at the end of the pistoncylin'der, an outlet chamber in communication with the valve box, theend of the valve box adjacent to the piston cylinder being of skeletonstructure and provided with valve seats on its inner face, a cap for theopposite end of the valve box provided with a socket in its inner face,a valve guiding spindle fixed in the said skeleton end of the valve boxwith its free end entering the socket in the opposite end of the valvebox, a valve mounted to slide on said spindle, aspring for operating thevalve and a nut having a screw-threaded engagement with the spindleWithin the said socket for holding the spindle against vibration.

3. In an air compressor, a main compressor cylinder, a piston cylinderin '00- operative relation thereto, a valve box at the end of the pistoncylinder, an outlet chamber in communication with the valve box, one endof the valve box being of skeleton structure and the opposite endprovided with a cap having a socket in its inner face, avalve guidingspindle fixed in the skeleton end of the box and projecting into thesocket in the opposite end, an elastic disk located between the end'ofthe spindle and the bottom of the said socket, a nut shavingasc'rew-t-hreaded engagement with the end of the spindle within thesocket and adapted to bear against the disk to prevent leakage and holdthe spindle against vibration, a valve mounted to slide on the spindleand a spring for actuating the valve.

In testimony that I claim the foregoing as my invention, I have signedmy name in presence of two witnesses, this twenty-sixth day of October,1911.

F. GEORGE BARRY, C. S. SUNDGREN.

